This invention relates to a medical device particularly well suited for endoscopic applications, which device is in the form of a surgical pouch for isolating an internal bodily organ or tissue from surrounding tissue. The invention also relates to a method of preventing certain surgical adhesions, particularly ovarian adhesions, endoscopically using a surgical pouch.
As medical and hospital costs continue to increase, surgeons are constantly striving to develop advanced surgical techniques. Advances in the surgical field are often related to the development of operative techniques which involve less invasive surgical procedures and reduce overall patient trauma. In this manner, the length of hospital stays can be significantly reduced, and therefore the hospital and medical costs can be reduced as well.
One of the truly great advances in recent years to reduce the invasiveness of surgical procedures is endoscopic surgery. Endoscopic surgery involves the use of an endoscope, which is an instrument permitting the visual inspection and magnification of any cavity of the body. The endoscope is inserted through a tubular sheath, referred to as a cannula, after puncture through the wall of the body cavity with a trocar, which is a sharp-pointed instrument. The surgeon can then perform diagnostic and therapeutic procedures at the surgical site with the aid of specialized instrumentation designed to fit through additional cannulas providing openings into the desired body cavity as may be required.
In many surgical procedures, including those involved in endoscopic surgery, it is often necessary to isolate bodily tissue or organs from the surrounding tissue at the surgical site, so that surgical procedures can be performed without fear of contamination. This is especially challenging during endoscopic surgery because of the small openings through which such tissue or organs must be isolated.
In response to this need for medical devices to isolate bodily tissue endoscopically, numerous devices have recently been developed. The driving force behind the development of these devices has been the need to not only isolate tissue but also remove it once the tissue is isolated. Under these circumstances, it is necessary to fragment, or morcellate, the bodily tissue so that it can be readily removed through the small endoscopic openings.
The most effective devices recently developed for isolating and removing tissue endoscopically are surgical drawstring bags capable of being closed remotely from the surgical site. One such drawstring bag is disclosed in U.S. Pat. No. 5,037,379, in which the drawstring is long enough to allow the surgeon to grasp a looped portion of the drawstring outside of the body even after the bag has enclosed the desired bodily tissue at the internal surgical site. The surgeon can then use the looped drawstring portion to close the bag, and to pull the bag up through the cannula to remove the bag and its fragmented tissue contents when the surgical procedure is completed.
Another more sophisticated surgical drawstring device is disclosed in U.S. Ser. No. 679,893, filed Apr. 3, 1991. This device couples the benefits of a ligating instrument designed to ligate remote blood vessels endoscopically with a surgical bag for ensnaring bodily tissue. It represents an advantage over the device described in the '379 patent because the device is easier to insert through a cannula, to maneuver once it is within the body cavity, and to remove when the surgical procedure is completed.
The surgical drawstring bags referred to above have been designed to be used in combination with an endoscopic instrument for removing tissue. This instrument is called a tissue morcellator, and its use with a surgical bag is described in an article in General Surgery News, 11 (10) 1990. This article illustrates the feasibility of laparoscopic nephrectomy, which is an endoscopic procedure for excising a kidney, by first enclosing the desired kidney in a nylon drawstring entrapment sack and then using a tissue morcellator to fragment and aspirate the kidney from the sack.
Even older designs of drawstring surgical bags could be modified for use in endoscopic procedures. For example, page 24 the 1959 Davol Rubber Company catalogue describes a drawstring surgical bag for isolating the small bowel. Another interesting concept is described in U.S. Pat. No. 4,428,375. This patent describes a drawstring mesh or net bag for encapsulating a fractured organ, particularly a traumatized spleen, during surgical repair. The bag is intended to conform to the organ shape and compress the organ sufficiently to close any organ fractures and provide hemostasis. The bag has a plurality of drawstrings to aid in conforming the bag to the organ. Similar type devices for enclosing fractured or damaged organs are described in U.S. Pat. Nos. 4,878,890; 2,143,910 and 3,983,863.
Finally, U.S. Pat. No. 4,991,593 describes a flexible surgical bag for enclosing a body organ. The bag provides means for limiting the closure of the bag to prevent injury to the enclosed body organ.
While all of these surgical bags simplify and facilitate numerous surgical procedures, including endoscopic procedures, the surgical bags of the prior art suffer from a major drawback. Specifically, none of the surgical bags disclosed are well adapted for use during an endoscopic technique in which the bag is to remain intact after surgery is completed. Ideally, implantable surgical devices, including surgical bags, are bioabsorbable when exposed to moist bodily tissue to prevent contamination or unwanted tissue reaction. In other words, when such a bag has accomplished its task, it is desirable in certain instances for the material from which the bag is composed to break down into small components which can be readily passed through the system without undesirable side effects.
Even though the prior art has described the use of bioabsorbable surgical bags (see, for example, U.S. Ser. No. 679,893, filed Apr. 3, 1991), the drawstring closure means described for those bags is ill-suited for endoscopic surgical techniques. Most of the bags described in the art utilize relatively rigid, nonabsorbable threads as the drawstrings for the bag, regardless whether the bag is intended to be bioabsorbable or nonabsorbable. The use of such a drawstring thread has found widespread acceptance because its relative rigidity helps to keep the mouth of the bag open, which is very important when working in an endoscopic field, and the surgeon needs the ability to place the desired body organ or tissue inside the bag.
Unfortunately, the use of rigid, nonabsorbable drawstring threads for surgical bags is unacceptable because such a thread could easily cause adverse tissue reaction since it remains indefinitely within the bodily tissue. Alternatively, the descriptions for the prior art drawstring bags include the potential use of absorbable threads in conjunction with the bag. While the combination of an absorbable thread drawstring with the bag would be particularly desirable when the drawstring bag is intended to remain intact at the surgical site, desirable absorbable threads are by nature very compliant and limp. These absorbable threads would not have the properties required to keep the mouth of the bag open before closure. This creates a particularly cumbersome problem for the surgeon during endoscopic surgery, because it then becomes much more difficult for the surgeon to place the desired bodily organ or tissue inside the bag when the mouth of the bag fails to remain open. For these reasons, a new surgical drawstring bag is needed to accommodate those applications where it is desired to use a bioabsorbable bag during endoscopic surgery.
In other endoscopic surgical procedures, it is often necessary or desired to prevent surgical adhesions. Adhesions are unwanted tissue growth which occurs following surgery from the manipulation of tissue, or the rubbing together of organs during the surgical procedure. Numerous methods have been described to prevent the occurrence of adhesions, one of them being the placement of an absorbable barrier fabric between layers of adjacent tissue or organs to prevent unwanted tissue growth following surgery. See, for example, U.S. Pat. Nos. 4,840,626 and 5,002,551.
A particularly significant problem caused by surgical adhesions is infertility when adhesions form on the ovaries. While the use of the barrier fabrics described in the patents of the preceding paragraph is acceptable for preventing adhesions at numerous locations within the body, the prevention of adhesions with such a barrier fabric on the ovaries is especially difficult because of the shape of the ovary. Since the ovary is generally round in shape, it is practically impossible to effectively cover the entire surface area of the ovary with the flat, rectangular-shaped barrier fabric described above. In view of the problem still remaining with preventing adhesions during surgery, particularly ovarian adhesions, it would be helpful to the medical community if a medical device could be developed that would facilitate the prevention of such adhesions.
In view of the deficiencies inherent in the prior art drawstring surgical bags and their use, particularly bags which are to remain intact within the bodily tissue following surgery, it would be desirable to have a drawstring surgical bag which is particularly well suited for endoscopic applications requiring the bioabsorption of the bag and its drawstrings. More specifically, what is needed is such a surgical drawstring bag whose mouth can remain open without difficulty when a bodily organ or tissue is desired to be implanted within the bag, yet will not cause inflammatory or toxic reactions to tissue when the bag remains in place after surgery. Additionally, it would be particularly desirable if a method could be developed for use in combination with a drawstring bag for preventing ovarian adhesions.